This study presents the synthesis, characterization and Hirshfeld surface analysis of a small organic ammonium salt, C2H7BrN+·Br−. Small cations like the one in the title compound are considered promising components of hybrid perovskites, crucial for optoelectronic and photovoltaic applications. While the incorporation of this organic cation into various hybrid perovskite structures has been explored, its halide salt counterpart remains largely uninvestigated. The obtained structural results are valuable for the synthesis and phase analysis of hybrid perovskites. The title compound crystallizes in the solvent-free form in the centrosymmetric monoclinic space group P21/c, featuring one organic cation and one bromide anion in its asymmetric unit, with a torsion angle of −64.8 (2)° between the ammonium group and the bromine substituent, positioned in a gauche conformation. The crystal packing is predominantly governed by Br⋯H inter­actions, which constitute 62.6% of the overall close atom contacts.

The title compound, [Re(C17H22N3O2S)(CO)3] is a net neutral fac-Re(I)(CO)3 complex of the 4-methyl­biphenyl sulfonamide derivatized di­ethyl­enetri­amine ligand. The NNN-donor monoanionic ligand coordinates with the Re core in tridentate fashion, establishing an inner coordination sphere resulting in a net neutral complex. The complex possesses pseudo-octa­hedral geometry where one face of the octa­hedron is occupied by three carbonyl ligands and the other faces are occupied by one sp2 nitro­gen atom of the sulfonamide group and two sp3 nitro­gen atoms of the dien backbone. The Re—Nsp2 bond distance, 2.173 (4) Å, is shorter than the Re—Nsp3 bond distances, 2.217 (5) and 2.228 (6) Å, and is similar to the range reported for typical Re—Nsp2 bond lengths (2.14 to 2.18 Å).

The title compound, C8H11PS, which melts below room temperature, was crystallized at low temperature. The P—S bond length is 1.9623 (5) Å and the major contributors to the Hirshfeld surface are H⋯H (58.1%), S⋯H/H⋯S (13.4%) and C⋯H/H⋯C contacts (11.7%).

The mol­ecular structure of tricarbon­yl[η4-6-exo-(tri­phenyl­phosphino)cyclo­hepta-2,4-dien-1-one]iron(0) tetra­fluoro­borate di­chloro­methane hemisolvate, [Fe(C28H22O4)(CO)3]BF4·0.5CH2Cl2, as determined by single-crystal X-ray diffraction is reported. The two independent tricarbon­yl[η4-6-exo-(tri­phenyl­phosphino)cyclo­hepta-2,4-dien-1-one] iron(0) cations and their corresponding anions form dimers, which constitute the asymmetric unit of the structure parallel to the (100) plane. Solid-state stability within that asymmetric unit as well as between neighboring dimeric units is afforded by C—H⋯O and C—H⋯F hydrogen bonds and C—H⋯π and Y—X⋯π (Y = B, C; X = F, O) inter­actions, which yield diperiodic sheets and a three-dimensional extended network.

The crystal structure of the title 2:1 mol­ecular complex between 2-(allyl­thio)­pyridine and 1,2,4,5-tetra­fluoro-3,6-di­iodo­benzene, C6F4I2·2C8H9NS, at 100 K has been determined in the monoclinic space group P21/c. The most noteworthy characteristic of the complex is the halogen bond between iodine and the pyridine ring with a short N⋯I contact [2.8628 (12) Å]. The Hirshfeld surface analysis shows that the hydrogen⋯hydrogen contacts dominate the crystal packing with a contribution of 32.1%.

The crystal structure of 1,2,3,4-tetra­hydro­isoquinolin-2-ium (2S,3S)-3-carb­oxy-2,3-di­hydroxy­propano­ate monohydrate, C9H12N+·C4H5O6−·H2O, at 115 K shows ortho­rhom­bic symmetry (space group P212121). The hydrogen tartrate anions and solvent water mol­ecules form an intricate diperiodic O—H⋯O hydrogen-bond network parallel to (001). The tetra­hydro­isoquinolinium cations are tethered to the anionic hydrogen-bonded layers through N—H⋯O hydrogen bonds. The crystal packing in the third direction is achieved through van der Waals contacts between the hydro­carbon tails of the tetra­hydro­isoquinolinium cations, resulting in hydro­phobic and hydro­philic regions in the crystal structure.

The crystal structure of bis­muth penta­fluoride, BiF5, was rerefined from single-crystal data. BiF5 crystallizes in the α-UF5 structure type in the form of colorless needles. In comparison with the previously reported crystal-structure model [Hebecker (1971). Z. Anorg. Allg. Chem. 384, 111–114], the lattice parameters and fractional atomic coordinates were determined to much higher precision and all atoms were refined anisotropically, leading to a significantly improved structure model. The Bi atom (site symmetry 4/m..) is surrounded by six F atoms in a distorted octa­hedral coordination environment. The [BiF6] octa­hedra are corner-linked to form infinite straight chains extending parallel to [001]. Density functional theory (DFT) calculations at the PBE0/TZVP level of theory were performed on the crystal structure of BiF5 to calculate its IR and Raman spectra. These are compared with experimental data.

In the title compound, C19H18BrFN2O, the pyrrolidine ring adopts an envelope conformation. In the crystal, mol­ecules are linked by inter­molecular N—H⋯O, C—H⋯O, C—H⋯F and C—H⋯Br hydrogen bonds, forming a three-dimensional network. In addition, C—H⋯π inter­actions connect mol­ecules into ribbons along the b-axis direction, consolidating the mol­ecular packing. The inter­molecular inter­actions in the crystal structure were qu­anti­fied and analysed using Hirshfeld surface analysis.

A new mononuclear complex, penta­aqua­(cucurbit[6]uril-κ2O,O')(nitrato-κ2O,O')praseodymium(III) dinitrate 9.56-hydrate, [Pr(NO3)(CB6)(H2O)5](NO3)2·9.56H2O (1), was obtained as outcome of the hydro­thermal reaction between the macrocyclic ligand cucurbit[6]uril (CB6, C36H36N24O12) with a tenfold excess of Pr(NO3)3·6H2O. Complex 1 crystallizes in the P21/n space group with two crystallographically independent but chemically identical [Pr(CB6)(NO3)(H2O)5]2+ complex cations, four nitrate counter-anions and 19.12 inter­stitial water mol­ecules per asymmetric unit. The nona­coordinated PrIII in 1 are located in the PrO9 coordination environment formed by two carbonyl O atoms from bidentate cucurbit[6]uril units, two oxygen atoms from the bidentate nitrate anion and five water mol­ecules. Considering the differences in Pr—O bond distances and O—Pr—O angles in the coordination spheres, the coordination polyhedrons of the two PrIII atoms can be described as distorted spherical capped square anti­prismatic and muffin polyhedral.

In the title compound, C14H14O4, the dihedral angle between the coumarin ring system (r.m.s deviation = 0.016 Å) and the penta­noate ring is 36.26 (8)°. A short intra­molecular C—H⋯O contact of 2.40 Å is observed. Hirshfeld surface analysis reveals that 46.1% of the inter­molecular inter­actions are from H⋯H contacts, 28.6% are from H⋯O/O⋯H contacts and 14.7% are from H⋯C/C⋯H.

The title compound, [Ni(NCS)2(C6H7N)2]n, was prepared by the reaction of Ni(NCS)2 with 4-methyl­pyridine in water. Its asymmetric unit consists of two crystallographically independent NiII cations, of which one is located on a twofold rotational axis whereas the second occupies a center of inversion, two independent thio­cyanate anions and two independent 4-methyl­pyridine co­ligands in general positions. Each NiII cation is octa­hedrally coordinated by two 4-methyl­pyridine coligands as well as two N- and two S-bonded thio­cyanate anions. One of the cations shows an all-trans, the other a cis–cis–trans configuration. The metal centers are linked by pairs of μ-1,3-bridging thio­cyanate anions into [101] chains. X-ray powder diffraction shows that a pure crystalline phase has been obtained and thermogravimetry coupled to differential thermoanalysis reveals that the title compound loses half of the 4-methyl­pyridine coligands and transforms into Ni(NCS)2(C6H7N). Nearly pure samples of this compound can be obtained by thermal annealing and a Rietveld refinement demonstrated that it is isotypic to its recently reported Cd analog [Neumann et al., (2020). CrystEngComm. 22, 184–194] In its crystal structure, the metal cations are linked by one μ-1,3(N,S)- and one μ-1,3,3(N,S,S)-bridging thio­cyanate anion into single chains that condense via the μ-1,3,3(N,S,S)-bridging anionic ligands into double chains.

The pyrazolo­pyrimidine moiety in the title mol­ecule, C13H12N4S, is planar with the methyl­sulfanyl substituent lying essentially in the same plane. The benzyl group is rotated well out of this plane by 73.64 (6)°, giving the mol­ecule an approximate L shape. In the crystal, C—H⋯π(ring) inter­actions and C—H⋯S hydrogen bonds form tubes extending along the a axis. Furthermore, there are π–π inter­actions between parallel phenyl rings with centroid-to-centroid distances of 3.8418 (12) Å. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (47.0%), H⋯N/N⋯H (17.6%) and H⋯C/C⋯H (17.0%) inter­actions. The volume of the crystal voids and the percentage of free space were calculated to be 76.45 Å3 and 6.39%, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the cohesion of the crystal structure is dominated by the dispersion energy contributions.

A new quinoline derivative, namely, 6-(di­ethyl­amino)-4-phenyl-2-(pyridin-2-yl)quinoline, C24H23N3 (QP), and its MnII complex aqua-1κO-di-μ-chlorido-1:2κ4Cl:Cl-di­chlorido-1κCl,2κCl-bis­[6-(di­ethyl­amino)-4-phenyl-2-(pyridin-2-yl)quinoline]-1κ2N1,N2;2κ2N1,N2-dimanganese(II), [Mn2Cl4(C24H23N3)2(H2O)] (MnQP), were synthesized. Their compositions have been determined with ESI-MS, IR, and 1H NMR spectroscopy. The crystal-structure determination of MnQP revealed a dinuclear complex with a central four-membered Mn2Cl2 ring. Both MnII atoms bind to an additional Cl atom and to two N atoms of the QP ligand. One MnII atom expands its coordination sphere with an extra water mol­ecule, resulting in a distorted octa­hedral shape. The second MnII atom shows a distorted trigonal–bipyramidal shape. The UV–vis absorption and emission spectra of the examined compounds were studied. Furthermore, when investigating the aggregation-induced emission (AIE) properties, it was found that the fluorescent color changes from blue to green and eventually becomes yellow as the fraction of water in the THF/water mixture increases from 0% to 99%. In particular, these color and intensity changes are most pronounced at a water fraction of 60%. The crystal structure contains disordered solvent mol­ecules, which could not be modeled. The SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9–18] was used to obtain information on the type and qu­antity of solvent mol­ecules, which resulted in 44 electrons in a void volume of 274 Å3, corresponding to approximately 1.7 mol­ecules of ethanol in the unit cell. These ethanol mol­ecules are not considered in the given chemical formula and other crystal data.

The crystal structures of 4-benzyl-1H-pyrazole (C10H10N2, 1) and 3,5-di­amino-4-benzyl-1H-pyrazole (C10H12N4, 2) were measured at 150 K. Although its different conformers and atropenanti­omers easily inter­convert in solution by annular tautomerism and/or rotation of the benzyl substituent around the C(pyrazole)—C(CH2) single bond (as revealed by 1H NMR spectroscopy), 1 crystallizes in the non-centrosymmetric space group P21. Within its crystal structure, the pyrazole and phenyl aromatic moieties are organized into alternating bilayers. Both pyrazole and phenyl layers consist of aromatic rings stacked into columns in two orthogonal directions. Within the pyrazole layer, the pyrazole rings form parallel catemers by N—H⋯N hydrogen bonding. Compound 2 adopts a similar bilayer structure, albeit in the centrosymmetric space group P21/c, with pyrazole N—H protons as donors in N—H⋯π hydrogen bonds with neighboring pyrazole rings, and NH2 protons as donors in N—H⋯N hydrogen bonds with adjacent pyrazoles and other NH2 moieties. The crystal structures and supra­molecular features of 1 and 2 are contrasted with the two known structures of their analogs, 3,5-dimethyl-4-benzyl-1H-pyrazole and 3,5-diphenyl-4-benzyl-1H-pyrazole.

The reaction of cadmium iodide with 3-amino­pyrazole (3-apz) in ethano­lic solution leads to tautomerization of the ligand and the formation of crystals of the title compound, catena-poly[[di­iodido­cadmium(II)]-bis­(μ-3-amino-1H-pyrazole)-κ2N2:N3;κ2N3:N2], [CdI2(C3H5N3)2]n or [CdI2(3-apz)2]n. Its asymmetric unit consists of a half of a Cd2+ cation, an iodide anion and a 3-apz mol­ecule. The Cd2+ cations are coordinated by two iodide anions and two 3-apz ligands, generating trans-CdN4I2 octa­hedra, which are linked into chains by pairs of the bridging ligands. In the crystal, the ligand mol­ecules and iodide anions of neighboring chains are linked through inter­chain hydrogen bonds into a di-periodic network. The inter­molecular contacts were qu­anti­fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative qu­anti­tative contributions of the weak inter­molecular contacts.

The compounds 2',3',4',6'-tetra-O-acetyl-β-d-gluco­pyranosyl N'-cyano-N-phenyl­carbamimido­thio­ate (C22H25N3O9S, 5a), 2',3',4',6'-tetra-O-acetyl-β-d-galacto­pyranosyl N'-cyano-N-phenyl­carbamimido­thio­ate, (C22H25N3O9S, 5b), 2',3',4',6'-tetra-O-acetyl-β-d-galacto­pyranosyl N'-cyano-N-methyl­carbamimido­thio­ate (C17H23N3O9S, 5c), and 2',3',4',6'-tetra-O-acetyl-β-d-galacto­pyranosyl N'-cyano-N-p-tolyl­carbamimido­thio­ate (C23H27N3O9S, 5d) all crystallize in P212121 with Z = 4. For all four structures, the configuration across the central (formal) C=N(CN) double bond of the carbamimido­thio­ate group is Z. The torsion angles C5—O1—C1—S (standard sugar numbering) are all close to 180°, confirming the β position of the substituent. Compound 5b involves an intra­molecular hydrogen bond N—H⋯O1; in 5c this contact is the weaker branch of a three-centre inter­action, whereas in 5a and 5d the H⋯O distances are much longer and do not represent significant inter­actions. The C—N bond lengths at the central carbon atom of the carbamimido­thio­ate group are almost equal. All C—O—C=O torsion angles of the acetyl groups correspond to a synperiplanar geometry, but otherwise all four mol­ecules display a high degree of conformational flexibility, with many widely differing torsion angles for equivalent groups. In the crystal packing, 5a, 5c and 5d form layer structures involving the classical hydrogen bond N—H⋯Ncyano and a variety of ‘weak’ hydrogen bonds C—H⋯O or C—H⋯S. The packing of 5b is almost featureless and involves a large number of borderline ‘weak’ hydrogen bonds. In an appendix, a potted history of wavelength preferences for structure determination is presented and it is recommended that, even for small organic crystals in non-centrosymmetric space groups, the use of Mo radiation should be considered.

The asymmetric unit of the title compound is composed of two independent ion pairs of 4-(di­methyl­amino)­pyridin-1-ium 8-hy­droxy­quinoline-5-sulfonate (HDMAP+·HqSA−, C7H11N2+·C9H6NO4S−) and neutral N,N-di­methyl­pyridin-4-amine mol­ecules (DMAP, C7H10N2), co-crystallized as a 1:1:1 HDMAP+:HqSA−:DMAP adduct in the monoclinic system, space group Pc. The compound has a layered structure, including cation layers of HDMAP+ with DMAP and anion layers of HqSA− in the crystal. In the cation layer, there are inter­molecular N—H⋯N hydrogen bonds between the protonated HDMAP+ mol­ecule and the neutral DMAP mol­ecule. In the anion layer, each HqSA− is surrounded by other six HqSA−, where the planar network structure is formed by inter­molecular O—H⋯O and C—H⋯O hydrogen bonds. The cation and anion layers are linked by inter­molecular C—H⋯O hydrogen bonds and C—H⋯π inter­actions.

In the title mol­ecule, C11H11BrO3, the di­hydro­indene moiety is essentially planar but with a slight twist in the saturated portion of the five-membered ring. The meth­oxy groups lie close to the above plane. In the crystal, π-stacking inter­actions between six-membered rings form stacks of mol­ecules extending along the a-axis direction, which are linked by weak C—H⋯O and C—H⋯Br hydrogen bonds. A Hirshfeld surface analysis was performed showing H⋯H, O⋯H/H⋯O and Br⋯H/H⋯Br contacts make the largest contributions to inter­molecular inter­actions in the crystal.

In the title complex, [U(C10H7N3O3)O2(CH3OH)]n, the UVI cation has a typical penta­gonal–bipyramidal environment with the equatorial plane defined by one N and two O atoms of one doubly deprotonated 2-[5-(2-hy­droxy­phen­yl)-1H-1,2,4-triazol-3-yl]acetic acid ligand, a carboxyl­ate O atom of the symmetry-related ligand and the O atom of the methanol mol­ecule [U—N/Oeq 2.256 (4)–2.504 (5) Å]. The axial positions are occupied by two oxide O atoms. The equatorial atoms are almost coplanar, with the largest deviation from the mean plane being 0.121 Å for one of the O atoms. The benzene and triazole rings of the tetra­dentate chelating–bridging ligand are twisted by approximately 21.6 (2)° with respect to each other. The carboxyl­ate group of the ligand bridges two uranyl cations, forming a neutral zigzag chain reinforced by a strong O—H⋯O hydrogen bond. In the crystal, adjacent chains are linked into two-dimensional sheets parallel to the ac plane by C/N—H⋯N/O hydrogen bonding and π–π inter­actions. Further weak C—H⋯O contacts consolidate the three-dimensional supra­molecular architecture. In the solid state, the compound shows a broad medium intensity LMCT transition centred around 463 nm, which is responsible for its red colour.

Two new [1-(phenyl­sulfon­yl)-1H-indol-2-yl]methanamine derivatives, namely, N-(3-meth­oxy­phen­yl)-N-{[1-(phenyl­sulfon­yl)-1H-indol-2-yl]meth­yl}acetamide, C24H22N2O4S, (I), and N-(2,5-di­meth­oxy­phen­yl)-N-{[1-(phenyl­sulfon­yl)-1H-indol-2-yl]meth­yl}benzene­sulfonamide, C29H26N2O6S2, (II), reveal a nearly orthogonal orientation of their indole ring systems and sulfonyl-bound phenyl rings. The sulfonyl moieties adopt the anti-periplanar conformation. For both compounds, the crystal packing is dominated by C—H⋯O bonding [C⋯O = 3.312 (4)–3.788 (8) Å], with the structure of II exhibiting a larger number, but weaker bonds of this type. Slipped π–π inter­actions of anti­parallel indole systems are specific for I, whereas the structure of II delivers two kinds of C—H⋯π inter­actions at both axial sides of the indole moiety. These findings agree with the results of Hirshfeld surface analysis. The primary contributions to the surface areas are associated with the contacts involving H atoms. Although II manifests a larger fraction of the O⋯H/H⋯O contacts (25.8 versus 22.4%), most of them are relatively distal and agree with the corresponding van der Waals separations.

The aryl diester compound, 2-methyl-1,4-phenyl­ene bis­(3,5-di­bromo­benzoate), C21H12Br4O4, was synthesized by esterification of methyl hydro­quinone with 3,5-di­bromo­benzoic acid. A crystalline sample was obtained by cooling a sample of the melt (m.p. = 502 K/DSC) to room temperature. The mol­ecular structure consists of a central benzene ring with anti-3,5-di­bromo­benzoate groups symmetrically attached at the 1 and 4 positions and a methyl group attached at the 2 position of the central ring. In the crystal structure (space group Poverline{1}), mol­ecules of the title aryl diester are located on inversion centers imposing disorder of the methyl group and H atom across the central benzene ring. The crystal structure is consolidated by a network of C—H⋯Br hydrogen bonds in addition to weaker and offset π–π inter­actions involving the central benzene rings as well as the rings of the attached 3,5-di­bromo­benzoate groups.

The crystal structures of two inter­mediates, 4-amino-3,5-di­fluoro­benzo­nitrile, C7H4F2N2 (I), and ethyl 4-amino-3,5-di­fluoro­benzoate, C9H9F2NO2 (II), along with a visible-light-responsive azo­benzene derivative, diethyl 4,4'-(diazene-1,2-di­yl)bis­(3,5-di­fluoro­benzoate), C18H14F4N2O4 (III), obtained by four-step synthetic procedure, were studied using single-crystal X-ray diffraction. The mol­ecules of I and II demonstrate the quinoid character of phenyl rings accompanied by the distortion of bond angles related to the presence of fluorine substituents in the 3 and 5 (ortho) positions. In the crystals of I and II, the mol­ecules are connected by N—H⋯N, N—H⋯F and N—H⋯O hydrogen bonds, C—H⋯F short contacts, and π-stacking inter­actions. In crystal of III, only stacking inter­actions between the mol­ecules are found.

The title compound, bis­[di­thio­bis­(formamidinium)] hexa­bromido­ruthenium dibromide trihydrate, [(NH2)2CSSC(NH2)2]2[RuBr6]Br2·3H2O, crystallizes in the ortho­rhom­bic system, space group Cmcm, Z = 4. The [RuBr6]2− anionic complex has an octa­hedral structure. The Ru—Br distances fall in the range 2.4779 (4)–2.4890 (4) Å. The S—S and C—S distances are 2.0282 (12) and 1.783 (2) Å, respectively. The H2O mol­ecules, Br− ions, and NH2 groups of the cation are linked by hydrogen bonds. The conformation of the cation is consolidated by intra­molecular O—H⋯Br, O—H⋯O, N—H⋯Br and N—H⋯O hydrogen bonds. The [(NH2)2CSSC(NH2)2]2+ cations form a hydrogen-bonded system involving the Br − ions and the water mol­ecules. Two Br − anions form four hydrogen bonds, each with the NH2 groups of two cations, thus linking the cations into a ring. The rings are connected by water mol­ecules, forming N—H⋯O—H⋯Br hydrogen bonds.

The dinuclear mol­ecule of the title compound, [Mo2(C9H13)2(CO)6] or [Mo(tBuCp)(CO)3]2 where tBu and Cp are tert-butyl and cyclo­penta­dienyl, is centrosymmetric and is characterized by an Mo—Mo bond length of 3.2323 (3) Å. Imposed by inversion symmetry, the tBuCp and the carbonyl ligands are in a transoid arrangement to each other. In the crystal, inter­molecular C—H⋯O contacts lead to the formation of layers parallel to the bc plane.

The structures of seven gold(III) halide derivatives of general formula LAuX3 (L = methyl­pyridines or di­methyl­pyridines, X = Cl or Br) are presented: tri­chlorido­(2-methyl­pyridine)­gold(III), [AuCl3(C6H7N)], 1 (as two polymorphs 1a and 1b); tri­bromido­(2-methyl­pyridine)­gold(III), [AuBr3(C6H7N)], 2; tri­bromido­(3-methyl­pyridine)­gold(III), [AuBr3(C6H7N)], 3; tri­bromido­(2,4-di­meth­yl­pyridine)­gold(III), [AuBr3(C7H9N)], 4; tri­chlorido­(3,5-di­methylpyridine)­gold(III), [AuCl3(C7H9N)], 5; tri­bromido­(3,5-di­methyl­pyridine)­gold(III), [AuBr3(C7H9N)], 6, and tri­chlorido­(2,6-di­methyl­pyridine)­gold(III), [AuCl3(C7H9N)], 7. Additionally, the structure of 8, the 1:1 adduct of 2 and 6, [AuBr3(C6H7N)]·[AuBr3(C7H9N)], is included. All the structures crystallize solvent-free, and all have Z' = 1 except for 5 and 7, which display crystallographic twofold rotation symmetry, and 4, which has Z' = 2. 1a and 2 are isotypic. The coordination geometry at the gold(III) atoms is, as expected, square-planar. Four of the crystals (1a, 1b, 2 and 8) were non-merohedral twins, and these structures were refined using the ‘HKLF 5’ method. The largest inter­planar angles between the pyridine ring and the coordination plane are observed for those structures with a 2-methyl substituent of the pyridine ring. The Au—N bonds are consistently longer trans to Br (average 2.059 Å) than trans to Cl (average 2.036 Å). In the crystal packing, a frequent feature is the offset-stacked and approximately rectangular dimeric moiety (Au—X)2, with anti­parallel Au—X bonds linked by Au⋯X contacts at the vacant positions axial to the coordination plane. The dimers are connected by further secondary inter­actions (Au⋯X or X⋯X contacts, `weak' C—H⋯X hydrogen bonds) to form chain, double chain (`ladder') or layer structures, and in several cases linked again in the third dimension. Only 1b and 7 contain no offset dimers; these structures instead involve C—H⋯Cl hydrogen bonds combined with Cl⋯Cl contacts (1b) or Cl⋯π contacts (7). The packing patterns of seven further complexes LAuX3 involving simple pyridines (taken from the Cambridge Structural Database) are compared with those of 1–8.

The di­hydro­imidazole ring in the title mol­ecule, C20H20N2O3S, is slightly distorted and the lone pair on the tri-coordinate nitro­gen atom is involved in intra-ring π bonding. The methyl­sulfanyl substituent lies nearly in the plane of the five-membered ring while the ester substituent is rotated well out of that plane. In the crystal, C—H⋯O hydrogen bonds form inversion dimers, which are connected along the a- and c-axis directions by additional C—H⋯O hydrogen bonds, forming layers parallel to the ac plane. The major contributors to the Hirshfeld surface are C⋯H/H⋯C, O⋯H/H⋯O and S⋯H/H⋯S contacts at 20.5%, 14.7% and 4.9%, respectively.

The title compound, C17H13BrN4O5, was synthesized by a Cu2Br2-catalysed Meldal–Sharpless reaction between 4-nitro­phen­oxy­acetic acid propargyl ether and para-bromo­phenyl­azide, and characterized by X-ray structure determination and 1H NMR spectroscopy. The mol­ecules, with a near-perpendicular orientation of the bromo­phenyl-triazole and nitro­phen­oxy­acetate fragments, are connected into a three-dimensional network by inter­molecular C—H⋯O and C—H⋯N hydrogen bonds (confirmed by Hirshfeld surface analysis), π–π and Br–π inter­actions.

In the crystal structure of the title compound, C26H36N2O4, the tripodal mol­ecule exists in a conformation in which the substituents attached to the central arene ring are arranged in an alternating order above and below the ring plane. The heterocyclic unit is inclined at an angle of 79.6 (1)° with respect to the plane of the benzene ring. In the crystal, the mol­ecules are connected via N—H⋯O bonds, forming infinite supra­molecular strands. Inter­strand association involves weak C—H⋯O and C—H⋯π inter­actions, with the pyridine ring acting as an acceptor in the latter case.

In the title compound, C31H28O4, the phenyl rings of the chalcone unit subtend a dihedral angle of 26.43 (10)°. The phenyl rings of the pendant benz­yloxy groups are orientated at 75.57 (13) and 75.70 (10)° with respect to their attached ring. In the crystal, weak C—H⋯O and C—H⋯π inter­actions link the mol­ecules. The inter­molecular inter­actions were qu­anti­fied and analysed using Hirshfeld surface analysis, which showed a breakdown into H⋯H (49.8%), H⋯C/C⋯H (33.8%) and H⋯O/O⋯H (13.6%) inter­actions with other types making negligible contributions.

The crystal structure of hexa­glycinium tetra-μ-iodido-octa­iodido­triplumbate, (C2H6NO2)6[Pb3I12] or (GlyH)6[Pb3I12], is reported. The compound crystallizes in the triclinic space group Poverline{1}. The [Pb3I12]6− anion is discrete and located around a special position: the central Pb ion located on the inversion center is holodirected, while the other two are hemidirected. The supra­molecular nature is mainly based on C—H⋯I, N—H⋯I, O—H⋯I and N—H⋯O hydrogen bonds. Dimeric cations of type (A+⋯A+) for the amino acid glycine are observed for the first time.

The title compound, poly[bis­(β-alaninium) [[di­bromido­plumbate]-di-μ-di­bromido]] {(C2H8NO2)2[PbBr4]}n or (β-AlaH)2PbBr4, crystallizes in the monoclinic space group P21/n. The (PbBr4)2− anion is located on a general position and has a two-dimensional polymeric structure. The Pb center is holodirected. The supra­molecular network is mainly based on O—H⋯Br, N—H⋯Br and N—H⋯O hydrogen bonds.

In the title mol­ecule, C25H29N5O, the di­hydro­quinoxaline unit is not quite planar (r.m.s. deviation = 0.030 Å) as there is a dihedral angle of 2.69 (3)° between the mean planes of the constituent rings and the mol­ecule adopts a hairpin conformation. In the crystal, the polar portions of the mol­ecules are associated through C—H⋯O and C—H⋯N hydrogen bonds and C—H⋯π(ring) and C=O⋯π(ring) inter­actions, forming thick layers parallel to the bc plane and with the n-octyl groups on the outside surfaces.

The title complex, (1,4,7,10,13,16-hexa­oxa­cyclo­octa­decane-1κ6O)(μ-oxalato-1κ2O1,O2:2κ2O1',O2')triphenyl-2κ3C-potassium(I)tin(IV), [KSn(C6H5)3(C2O4)(C12H24O6)] or K[18-Crown-6][(C6H5)3SnO4C2], was synthesized. The complex consists of a potassium cation coordinated to the six oxygen atoms of a crown ether mol­ecule and the two oxygen atoms of the oxalatotri­phenyl­stannate anion. It crystallizes in the monoclinic crystal system within the space group P21. The tin atom is coordinated by one chelating oxalate ligand and three phenyl groups, forming a cis-trigonal–bipyramidal geometry around the tin atom. The cations and anions form ion pairs, linked through carbonyl coordination to the potassium atoms. The crystal structure features C—H⋯O hydrogen bonds between the oxygen atoms of the oxalate group and the hydrogen atoms of the phenyl groups, resulting in an infinite chain structure extending along a-axis direction. The primary inter-chain inter­actions are van der Waals forces.

This study presents the synthesis, characterization and Hirshfeld surface analysis of the title mononuclear complex, [PdCl2(C12H14N4)]·C3H7NO. The compound crystalizes in the P21/c space group of the monoclinic system. The asymmetric unit contains one neutral complex Pd(HLc-Pe)Cl2 [HLc-Pe is 2-(3-cyclo­pentyl-1,2,4-triazol-5-yl)pyridine] and one mol­ecule of DMF as a solvate. The Pd atom has a square-planar coordination. In the crystal, mol­ecules are linked by inter­molecular N—H⋯O and C—H⋯N hydrogen bonds, forming layers parallel to the bc plane. A Hirshfeld surface analysis showed that the H⋯H contacts dominate the crystal packing with a contribution of 41.4%. The contribution of the N⋯H/H⋯N and H⋯O/O⋯H inter­actions is somewhat smaller, amounting to 12.4% and 5%, respectively.

The present study focuses on the synthesis and structural characterization of a novel dinuclear CuII complex, [tri­chlorido­copper(II)]-μ-chlorido-{bis­[2-hy­droxy-N'-(propan-2-yl­idene)benzohydrazide]copper(II)} monohydrate, [Cu2Cl4(C10H12N2O2)2]·H2O or [Cu(H2L)2(μ-Cl)CuCl3]·H2O [H2L = 2-hy­droxy-N'-(propan-2-yl­idene)benzohydrazide]. The complex crystallizes in the monoclinic space group P21/n with one mol­ecule of water, which forms inter­actions with the ligands. The first copper ion is penta-coordinated to two benzohydrazine-derived ligands via two nitro­gen and two oxygen atoms, and one bridging chloride, which is also coordinated by the second copper ion alongside three terminal chlorines in a distorted tetra­hedral geometry. The arrangement around the first copper ion exhibits a distorted geometry inter­mediate between trigonal bipyramidal and square pyramidal. In the crystal, chains are formed via inter­molecular inter­actions along the a-axis direction, with subsequent layers constructed through hydrogen-bonding inter­actions parallel to the ac plane, and through slipped π–π stacking inter­actions parallel to the ab plane, resulting in a three-dimensional network. The inter­molecular inter­actions in the crystal structure were qu­anti­fied and analysed using Hirshfeld surface analysis. Residual electron density from disordered methanol mol­ecules in the void space could not be reasonably modelled, thus a solvent mask was applied.

This study presents the synthesis, characterization and Hirshfeld surface analysis of 1-[6-bromo-2-(3-bromo­phen­yl)-1,2,3,4-tetra­hydro­quinolin-4-yl]pyrrolidin-2-one, C19H18Br2N2O. In the title compound, the pyrrolidine ring adopts a distorted envelope configuration. In the crystal, mol­ecules are linked by inter­molecular N—H⋯O, C—H⋯O and C—H⋯Br hydrogen bonds, forming a three-dimensional network. In addition, pairs of mol­ecules along the c axis are connected by C—H⋯π inter­actions. According to a Hirshfeld surface study, H⋯H (36.9%), Br⋯H/H⋯Br (28.2%) and C⋯H/H⋯C (24.3%) inter­actions are the most significant contributors to the crystal packing.

Propane-1,3-diaminium squarate dihydrate, C3H12N22+·C4O42−·2H2O, results from the proton-transfer reaction of propane-1,3-di­amine with squaric acid and subsequent crystallization from aqueous medium. The title compound crystallizes in the tetra­gonal crystal system (space group P4bm) with Z = 2. The squarate dianion belongs to the point group D4h and contains a crystallographic fourfold axis. The propane-1,3-diaminium dication exhibits a C2v-symmetric all-anti conformation and resides on a special position with mm2 site symmetry. The orientation of the propane-1,3-diaminium ions makes the crystal structure polar in the c-axis direction. The solid-state supra­molecular structure features a triperiodic network of strong hydrogen bonds of the N—H⋯O and O—H⋯O types.

The title compound, bis­[μ-2,2'-(4H-1,2,4-triazole-3,5-di­yl)di­acetato]­bis­[di­aqua­copper(II)] dihydrate, [Cu2(C6H5N3O4)2(H2O)4]·2H2O, is a dinuclear octa­hedral CuII triazole-based complex. The central copper atoms are hexa-coordinated by two nitro­gen atoms in the equatorial positions, two equatorial oxygen atoms of two carboxyl­ate substituents in position 3 and 5 of the 1,2,4-triazole ring, and two axial oxygen atoms of two water mol­ecules. Two additional solvent water mol­ecules are linked to the title mol­ecule by O—H⋯N and O⋯H—O hydrogen bonds. The crystal structure is built up from the parallel packing of discrete supra­molecular chains running along the a-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯O/O⋯H (53.5%), H⋯H (28.1%), O⋯O (6.3%) and H⋯C/C⋯H (6.2%) inter­actions. The crystal studied was twinned by a twofold rotation around [100].

In the title compound, C33H29ClN2O2, the two piperidine rings of the di­aza­bicyclo moiety adopt distorted-chair conformations. Inter­molecular C—H⋯π inter­actions are mainly responsible for the crystal packing. The inter­molecular inter­actions were qu­anti­fied and analysed using Hirshfeld surface analysis, revealing that H⋯H inter­actions contribute most to the crystal packing (52.3%). The mol­ecular structure was further optimized by density functional theory (DFT) at the B3LYP/6–31 G(d,p) level and is compared with the experimentally determined mol­ecular structure in the solid state.

The mol­ecular structure of the tripodal carbamoyl­methyl­phosphine oxide compound diethyl {[(5-[2-(di­eth­oxy­phosphor­yl)acetamido]-3-{2-[2-(di­eth­oxy­phos­phor­yl)acetamido]­eth­yl}pent­yl)carbamo­yl]meth­yl}phospho­nate, C25H52N3O12P3, features six intra­molecular hydrogen-bonding inter­actions. The phospho­nate groups have key bond lengths ranging from 1.4696 (12) to 1.4729 (12) Å (P=O), 1.5681 (11) to 1.5811 (12) Å (P—O) and 1.7881 (16) to 1.7936 (16) Å (P—C). Each amide group adopts a nearly perfect trans geometry, and the geometry around each phophorus atom resembles a slightly distorted tetra­hedron.

The two mol­ecules in the asymmetric unit of the title compound, C23H24N2O2S, have a structural overlap with an r.m.s. deviation of 0.82 Å. The piperidine rings adopt a distorted boat conformation. Intra- and inter­molecular C—H⋯O hydrogen bonds are responsible for the cohesion of the crystal packing. The inter­molecular inter­actions were qu­anti­fied and analysed using Hirshfeld surface analysis. The mol­ecular structure optimized by density functional theory (DFT) at the B3LYP/6–311++G(d,p)level is compared with the experimentally determined mol­ecular structure in the solid state.

The asymmetric unit of the title salt, C7H8N3+·C7H5O6S−, comprises two 1,3-di­hydro-2H-benzimidazol-2-iminium cations and two 2-hy­droxy-5-sulfobenzoate anions (Z' = 2). In the crystal, the mol­ecules inter­act through N—H⋯O, O—H⋯O hydrogen bonds and C—O⋯π contacts. The hydrogen-bonding inter­actions lead to the formation of layers parallel to (overline{1}01). Hirshfeld surface analysis revealed that H⋯H contacts contribute to most of the crystal packing with 38.9%, followed by H⋯O contacts with 36.2%.

In the title compound, C27H19O3N, the dihedral angle between the aromatic rings of the biphenyl unit is 38.14 (2)° and the C—O—C—C torsion angle in the benz­yloxy benzene fragment is 179.1 (2)°. In the crystal, the mol­ecules are linked by weak C—H⋯O inter­actions forming S(9) chains propagating along [010]. The most important contributions to the Hirshfeld surface arise from H⋯H (32.4%) and C⋯H/H⋯C (37.0%) contacts.

The benzimidazole moiety in the title mol­ecule, C19H25N5O, is almost planar and oriented nearly perpendicular to the triazole ring. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules into a network structure. There are no π–π inter­actions present but two weak C—H⋯π(ring) inter­actions are observed. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (62.0%), H⋯C/C⋯H (16.1%), H⋯N/N⋯H (13.7%) and H⋯O/O⋯H (7.5%) inter­actions. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via the dispersion energy contributions in the title compound.

Coordination compounds of polydentate nitro­gen ligands with metals are used extensively in research areas such as catalysis, and as models of complex active sites of enzymes in bioinorganic chemistry. Tris(2-pyridyl­meth­yl)amine (TPA) is a tripodal tetra­dentate ligand that is known to form coordination compounds with metals, including copper, iron and zinc. The related compound, tris­[(6-bromo­pyridin-2-yl)meth­yl]amine (TPABr3), C18H15Br3N4, which possesses a bromine atom on the 6-position of each of the three pyridyl moieties, is also known but has not been heavily investigated. The mol­ecular structure of TPABr3 as determined by X-ray diffraction is reported here. The TPABr3 molecule belongs to the triclinic, Poverline{1} space group and displays interesting intermolecular Br⋯Br interactions that provide a stabilizing influence within the molecule.

The synthesis of the title compound, [Zn(C4H6N2)6](NO3)2, is described. This complex consists of a central zinc metal ion surrounded by six 1-methyl­imidazole ligands, charge balanced by two nitrate anions. The complex crystallizes in the space group Poverline{3}. In the crystal, the nitrate ions are situated within the cavities created by the [Zn(N-Melm)6]2+ cations, serving as counter-ions. The three oxygen atoms of the nitrate ion engage in weak C—H⋯O inter­actions. In addition to single-crystal X-ray diffraction analysis, the complex was characterized using elemental analysis, 1H NMR, 13C NMR, and FTIR spectroscopy.

A new pyridine-fused seleno­diazo­lium salt, 3-(phenyl­selan­yl)[1,2,4]selena­diazolo[4,5-a]pyridin-4-ylium chloride di­chloro­methane 0.352-solvate, C12H9N2Se2+·Cl−·0.352CH2Cl2, was obtained from the reaction between 2-pyridyl­selenenyl chloride and phenyl­seleno­cyanate. Single-crystal structural analysis revealed the presence of C—H⋯N, C—H⋯Cl−, C—H⋯Se hydrogen bonds as well as chalcogen–chalcogen (Se⋯Se) and chalcogen–halogen (Se⋯Cl−) inter­actions. Non-covalent inter­actions were explored by DFT calculations followed by topological analysis of the electron density distribution (QTAIM analysis). The structure consists of pairs of seleno­diazo­lium moieties arranged in a head-to-tail fashion surrounding disordered di­chloro­methane mol­ecules. The assemblies are connected by C—H⋯Cl− and C—H⋯N hydrogen bonds, forming layers, which stack along the c-axis direction connected by bifurcated Se⋯Cl−⋯H—C inter­actions.

Crystallization of 5-nona­noyl-8-hy­droxy­quinoline in the presence of InCl3 in aceto­nitrile yields a dinuclear InIII complex crystallizing in the space group Poverline{1}. In this complex, [In2(C18H22NO2)2Cl4(H2O)2], each indium ion is sixfold coordinated by two chloride ions, one water mol­ecule and two 8-quinolino­late ions. The crystal of the title complex is composed of two-dimensional supra­molecular aggregates, resulting from the linkage of the Owater—H⋯O=C and Owater—H⋯Cl hydrogen bonds as well as bifurcated Carene—H⋯Cl contacts.

The crystal structure of the title compound C20H17NO2S features hydrogen-bonding and C—H⋯π inter­actions. Hirshfeld surface analysis revealed that H⋯H, C⋯H/H⋯C and O⋯H/H⋯O inter­actions make a major contribution to the crystal packing. Docking studies were carried out to determine the binding affinity and inter­action profile of the title compound with EGFR kinase, a member of the ErbB family of receptor tyrosine kinases, which is crucial for processes such as cell proliferation and differentiation. The title compound shows a strong binding affinity with EGFR kinase, with the most favourable conformation having a binding energy of −8.27 kcal mol−1 and a predicted IC50 of 870.34 nM, indicating its potential as a promising candidate for targeted lung cancer therapy.

When reacted in dry, degassed toluene, [Ir(COD)Cl]2 (COD = cyclo­octa-1,5-diene) and 2 equivalents of 2-(di-tert-butyl­phosphinito)anthra­quinone (tBuPOAQH) were found to form a unique tri-iridium compound consisting of one monoanionic dinuclear tri-μ-chlorido complex bearing one bidentate tBuPOAQ ligand per iridium, which was charge-balanced by an outer sphere [Ir(toluene)(COD)]+ ion, the structure of which has not previously been reported. This product, which is a toluene solvate, namely, (η2:η2-cyclo­octa-1,5-diene)(η6-toluene)­iridium(I) tri-μ-chlorido-bis­({3-[(di-tert-butyl­phosphan­yl)­oxy]-9,10-dioxoanthracen-2-yl}hydridoiridium(III)) toluene monosolvate, [Ir(C7H8)(C8H12)][Ir2H2(C22H24O3P)2Cl3]·C7H8 or [Ir(toluene)(COD)][Ir(κ-P,C-tBuPOAQ)(H)]2(μ-Cl)3]·toluene, formed as small orange platelets at room temperature, crystallizing in the triclinic space group Poverline{1}. The cation and anion are linked via weak C—H⋯O inter­actions. The stronger inter­molecular attractions are likely the offset parallel π–π inter­actions, which occur between the toluene ligands of pairs of inverted cations and between pairs of inverted anthra­quinone moieties, the latter of which are capped by toluene solvate mol­ecules, making for π-stacks of four mol­ecules each. The related ligand, 2-(di-tert-butyl­phosphinometh­yl)-anthra­quinone (tBuPCAQH), did not form crystals suitable for X-ray diffraction under analogous reaction conditions. However, when the reaction was conducted in chloro­form, yellow needles readily formed following addition of 1 atm of carbon monoxide. Diffraction studies revealed a neutral, dinuclear, di-μ-chlorido complex, di-μ-chlorido-bis­(carbon­yl{3-[(di-tert-butyl­phosphan­yl)­oxy]-9,10-dioxoanthracen-2-yl}hydridoiridium(I)), [Ir2H2(C23H26O2P)2Cl2(CO)2] or [Ir(κ-P,C-tBuPCAQ)(H)(CO)(μ-Cl)]2, Ir2C48H54Cl2O6P2, again crystallizing in space group Poverline{1}. Offset parallel π–π inter­actions between anthra­quinone groups of adjacent mol­ecules link the mol­ecules in one dimension.